Hologram reproducing apparatus

Abstract

A compact and low-cost hologram reproducing apparatus with a simple mechanism is provided. A light source 1 and a lens 11 for generating parallel light are provided on an inner surface of a housing 5 . By changing the angle of a biaxially driven galvanometer mirror 2 provided at an appropriate position opposing the light source 1 and the lens 11 , reflected light is applied two-dimensionally, in the vertical and horizontal directions, on a recording element 3 mounted below and adjacent to the housing, and is entered as reference light in holograms. Further, light beams exiting from the holograms are received at the same optimal position on a light-receiving element 4 disposed in an upper part of the housing. The received light is subjected to data decoding so as to reproduce read-only holograms.

1. A hologram reproducing apparatus for reproducing information recorded in a plurality of holograms that are two-dimensionally arranged on a recording medium, the apparatus comprising:
 a light source for emitting light into the holograms; 
 a light-receiving element for receiving reflected light beams exiting from the holograms; and 
 a movable mirror unit disposed at a position such as to oppose the light source, the movable mirror unit including:
 a reflecting mirror for reflecting the light from the light source into incident light, and 
 a driving unit for biaxially driving the reflecting mirror, 
 
 wherein the holograms are provided such that the reflected light beam exits from each hologram toward the light-receiving element, 
 wherein the angle of the reflecting mirror is changed by the driving unit so that the incident light enters the holograms, the incident light reaching a different hologram at a different position on the recording medium as the angle of the reflecting mirror changes, 
 and wherein the reflecting mirror rotates around two axes orthogonal to the light from the light source. 
 
   
   
     2. The hologram reproducing apparatus according to  claim 1 , wherein the light-receiving element receives the reflected light beams at a fixed position. 
   
   
     3. The hologram reproducing apparatus according to  claim 1 , wherein the light-receiving element and the recording medium oppose each other in a direction orthogonal to the light emitted from the light source. 
   
   
     4. The hologram reproducing apparatus according to  claim 3 , wherein the light source, the light-receiving element, and the movable mirror unit are mounted in the same housing. 
   
   
     5. The hologram reproducing apparatus according to  claim 1 , wherein the movable mirror unit is a galvanometer mirror. 
   
   
     6. The hologram reproducing apparatus according to  claim 1 , wherein the light source generates light beams having a plurality of wavelengths so as to reproduce holograms recorded on the recording medium by wavelength multiplexing.